How This Tool Works and Why It Exists
My name is Matt. I have spent most of my working life in labour and trades across Australia. When I started looking at getting into the housing market myself, I hit the same wall every homeowner hits: renovation costs that are vague, inconsistent and hard to compare.
Builders quote differently. Online estimates are all over the place. And with current housing prices and economic pressures making every dollar count, I wanted something that gave straight, well-sourced answers rather than rough guesses or sales pitches.
So I built RenovationCalculator.AU. It is the tool I wished existed when I started planning. Every estimate is anchored to real Australian industry data, adjusted for your city, and transparent about where the numbers come from. It is free, it requires no login, and it does not sell your details.
What this tool is
RenovationCalculator.AU is an independent renovation planning tool for Australian homeowners. It produces planning-level cost estimates for kitchens, bathrooms, decks, laundries and flooring across Sydney, Melbourne, Brisbane, Perth and Adelaide.
It is designed to help you sense-check budgets, understand what affects cost, and feel more informed before you request formal quotes from licensed contractors.
What this tool is not
This is not a builder. It does not produce formal quotes, construction specifications or project plans. The estimates here are planning benchmarks based on industry-average data. Your actual renovation cost will depend on your specific property, your material choices, site access, structural complexity and the individual pricing of contractors you engage.
We always recommend getting at least three written quotes from licensed contractors before committing to any renovation project.
How each estimate is built
National base cost
Every estimate starts from a national base rate calibrated against HIA and hipages benchmark data. For kitchens, the base is a per-linear-metre rate covering cabinetry, benchtop, appliance allowance, and trades rough-in. For bathrooms, it is a fixed base (demolition, plumbing, electrical, waterproofing) plus a per-square-metre variable for finishes. Each renovation type uses the model that best reflects how costs actually behave in practice.
City multiplier
Renovation costs vary significantly by city. The same project that costs $22,000 in Adelaide might cost $28,000 in Sydney, purely because of differences in trades labour rates, material supply chains and local demand. We apply a regional cost multiplier derived from HIA Trades Cost Indices and Master Builders Association state reports.
| City | Multiplier | What drives it |
|---|---|---|
| Sydney, NSW | 1.28× | High trades demand, infrastructure competition, HBCF insurance |
| Melbourne, VIC | 1.18× | 7-Star NatHERS requirements, strong renovation market |
| Brisbane, QLD | 1.32× | Post-flood rebuilding, 2032 Olympics, population growth |
| Perth, WA | 1.18× | FIFO labour competition, materials freight from eastern states |
| Adelaide, SA | 1.08× | Lower labour costs, shorter wait times, best value capital city |
Project-specific adjustments
On top of the base rate and city multiplier, the calculator adds project-specific cost components where relevant: copper materials loading (based on LME spot pricing), lead-free fittings compliance (AS/NZS 4020), waterproofing (AS 3740:2021 for wet areas), VIC 7-Star NatHERS compliance (where applicable), and BAL compliance surcharges for bushfire-prone areas.
Planning range
Every estimate includes a ±18% planning range. This reflects the typical variance between the lowest and highest quotes for comparable renovation projects. The midpoint is our best estimate; the range gives you a realistic band for budgeting purposes.
Data sources
Limitations and honesty
No calculator can predict what your specific renovation will cost. Site conditions, structural surprises, material availability and individual builder pricing all create real variance that no benchmark data can fully capture.
Some values in this calculator are industry estimates rather than published rates. The copper materials loading (~16.5%) is our estimate of the cost uplift on plumbing and electrical components based on LME pricing versus a 2020 baseline. It is not a government-published rate. Where we use estimates rather than verified data, we say so clearly in the calculator tooltips.
The most important thing this tool does is give you a well-sourced starting point so you can walk into a builder conversation with realistic expectations rather than guesswork. That is its purpose. It is not a substitute for formal quotes from licensed professionals.
Independence
RenovationCalculator.AU is not affiliated with any builder, contractor, materials supplier or insurance provider. We do not receive commissions or referral fees from any trade or building company. The estimates are not influenced by any commercial relationship. When we help connect users with builders through the quote form, this is a service we offer directly, not a third-party referral arrangement.
Contact
For questions, corrections, feedback or press enquiries: renovationcalculator@gmail.com
Based in Perth, Western Australia. Independent renovation planning resource since 2026.